.middle > div:nth-child(1) {
    display: flex;
    justify-content: center;
}

.middle > div:nth-child(1) > div {
    display: flex;
    justify-content: center;
    /*border: 1px solid red;*/
    align-items: center;
    background-color: rgb(51, 51, 51);
    padding: 0 20px;
    margin: 20px 0 50px;
}

.middle > div:nth-child(1) > div > div > a {
    display: flex;
    justify-content: center;
    width: 210px;
    line-height: 40px;
    align-items: center;
    /*border: 1px solid blue;*/
}

.middle > div:nth-child(1) > div > div:hover {
    background-color: red;
    color: white;
    /*width: 160px;*/
}


/*页面跳转栏*/
.middle > div:nth-child(3) > div {
    display: flex;
    justify-content: center;
    /*border: 1px solid red;*/
    /*align-items: center;*/
    margin-bottom: 40px;

}

.middle > div:nth-child(3) > div > a > div {
    border: 1px solid black;
    width: 22px;
    margin: 0 3px;
    line-height: 20px;
    align-items: center;
    display: flex;
    justify-content: center;
}

.middle > div:nth-child(3) > div > a > div:hover {
    background-color: black;
    width: 22px;
    color: white;
}

.middle > div:nth-child(2) {
    display: flex;
    justify-content: center;
    /*border: 1px solid red;*/
    margin-bottom: 20px;
}

.middle > div:nth-child(2) > div {
    display: flex;
    justify-content: center;
    width: 80%;
    /*border: 1px solid red;*/
    flex-wrap: wrap;
}

.middle > div:nth-child(2) > div > div {
    margin: 40px;

}

.middle > div:nth-child(2) > div > div>div:nth-child(2) {
    align-items: center;

}
.middle > div:nth-child(2) > div > div>div:nth-child(2)>div {
    display: flex;
    justify-content: center;
    align-items: center;
}
.middle > div:nth-child(2) > div > div>div:nth-child(2)>div:nth-child(2)>div:nth-child(2){
    color: red;
}